Suppression of proximity development with azine color developers



Patented Apr. 29, 1952 SUPPRESSION OF PROXIMITY DEVELOP- MENT WITH AZINE COLOR DEVELOPERS Robert C. Gunther, Easton, Pa., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application December 16, 1949, Serial No. 133,463

The present invention relates to a method of suppressing proximity development in the processing of multilayer color film to azine dyestuff images while employing 2,4-diamino-anilines for color development.

There is described in U. S. Patent 2,486,440. granted to Willy A. Schmidt and Vsevolod Tulagin, on November 1, 1949, a method of producing azine dyestufi images by color developing silver halide emulsions with a 2,4-diamino-aniline in the presence of a color former.

The azine dyes produced in this way have unusual stability and spectral characteristics, particularly when compared with the quinonimine or azomethine dyes produced with developers of the p-phenylenediamine type.

Despite the many recognized advantages of this new class of color developers, they possess one disadvantage which provides a somewhat serious problem in the use of the azine method. This disadvantage occurs in the development of multilayer film and is manifested by a loss of color rendition in the azine images formed in such material.

Such loss of color rendition has been found to be attributable to a phenomenon peculiar to the aforementioned azine processing which is characterized herein as proximity developmen The following explanation of such phenomenon will serve to give a better understanding of the objects of the present invention.

As is known, the conventional material employed at the present time in color photography is an integral tripack consisting essentially of three superimposed silver halide emulsion layers, the bottom layer being sensitized to red, the middle layer to green, and the top layer to blue. When such a tripack is exposed, the red densities of the picture are recorded in the bottom layer, the green densities in the middle layer, and the blue densities in the top layer. According to customary practice, the image formed i the respective layers is complementary in color to the light rays for which the particular layer is sensitized.

One of the best modes of constructing such tripacks involves the utilization in each of the three silver halide emulsion layers of a color former which is rendered non-diiiusing in the emulsions. Where such tripacks are of the reversible type, they are processed by developing first in a black and white developer, and finally in a color forming developer.

In the color development of such a tripack with a 2,4-diamino-aniline, the color developer reduces in any one layer the silver halide remaining after 7 Claims. (Cl. 95-2) 2 the first development and is itself oxidized to an active state capable of coupling with the color former present in that layer to form a positive dye image. Consequently in any one layer the amount of dye produced will be a function of the amount of residual silver halide in that layer and the resulting dye will be formed imagewise. Thus in each of the three layers of the tripack, one of the primary color densities (blue in the top layer, green in the middle layer, and red in the bottom layer) is accurately recorded in the form of a positive complementary dye image.

The coupling reaction between the migratory oxidized developer and the immobile color former in each layer is normally rapid so that the oxidized developer travels only a very short distance before encountering the color former molecule and coupling therewith. It often happens, however, that some dye may be produced in a particular layer by the coupling of a color former in that layer with an oxidized developer molecule that originated not in that particular layer but in one of the adjacent layers. Typically an oxidized developer molecule originating in the red sensitive layer may "escape from this layer without coupling and migrate to the green sensitive layer to couple with the color former molecule in that layer. As a result there will be produced in the green sensitive layer a certain amount of magenta dye which records not the green densities of the original picture, but red densities which should have been confined to the bottom or red sensitive layer. This migration of oxidized developer from one layer to an adjacent layer is the phenomeno known as proximity development.

It has been found that this tendency toward proximity development in the processing of tri-.

packs by the azine method while using 2,4-diamino-anilines for color development can be eliminated or greatly suppressed by utilizing in the azine color forming developer in aromatic hydroxy compound in the concentration range of l to 20 grams per liter. When such aromatic hydroxy compounds are so employed, the color separation, and consequently the brilliance of the color images are markedly improved over those obtained with the same azine color developer solution but free from such aromatic hydroxy compound.

The suppression of proximity development in the azine procedure while utilizing 2,4-diamino anilines for color development constitutes the purposes and objects of the present invention.

The 2,4-diamino-anilines which may be employed as the color developers for the contemplated procedure are of the type described in the aforementioned Schmidt and Tulagin Patent No. 2,486,440 and in my application Serial No. 101,913, filed June 28, 1949, and entitled Color Developers for the Production of Azine Dye Images, now Patent No. 2,570,116, issued October 2, 1951.

Specific examples of such developing agents are:

4 (/3 hydoxyethylamino) 6 (4' carboxymethoxy phenylamino) -metanilic acid.

4- (carboxymethylamino) -6- (4-methoxy phenylamino)-metanilic acid.

2- (p-sulfoethylamino) -4-phenylamino aniline.

4,6-di (,B-hydroxyethylamino) -metanilic acid.

4 (p3 hydroxyethylamino) 6 phenylaminometanilic acid.

2 (B hydroxyethylamino) 4 3 sulfoethylamino) -5-methyl aniline.

4 (,e-hydroxy-p-methyl-ethylamino)-6-phenylamino-metanilic acid.

4- (a-di (hydroxyethyl) ethylamino) -6-(3'-ethoxyphenylamino) -metanilic acid.

4 (,9 hydroxy ethylamino) 6-methy1aminometanilic acid.

4- (sulfomethylamino) -6- (methyl phenyl amino) metanilic acid.

Color formers to be used with the aforementioned developers to give yellow azine dye images are also described in my aforementioned applicacation Serial No. 101,913. These compounds are typified by the fact that they are open chain keto methylene compounds. Examples of such compounds are:

Acetoacetanilide.

N-l-naphthylacetoacetamide.

N,N -ethylenebisacetoacetamide.

p,p-Bi-o-acetoacetaniside.

N-2-naphthylbenzoylacetamide.

p,p-Biacetoacetanilide.

a,a' Terephthaloylbis-(3-chlcro-4,6-dimethoxy acetanilide) a-Benzoylacetanilide.

Preferably the color formers utilized contain a group rendering them non-migratory in the emulsion. Examples of such compounds are? 2 (m benzoylacetamidophenyl) -1-octadecyl-5- benzimidazolesulfonic acid.

3,3 ureylenebis 5 p benzoylacetamidobenzamide-benzene sulfonic acid.

2 p benzoylacetamidobenzamido 6-stearoy1- amino-p-toluenesulfonic acid.

2 (p benzoylacetamidophenyl) -1-octadecyl-5- benzimidasolesulfonic acid.

p-Cyanoacetyl-S-octadecenylsuccinalic acid.

Color formers capable of producing magenta dyestuff images are also described in my above entitled application as well as in application Serial No. 793,533, filed December 23, 1947 by Tulagin and Coles and entitled Magenta. Colored Phenazonium Dyestuff Images. now Patent No. 2,524,741, issued October 3, 1950. Preferably these color formers are: i-halogen- 8-hydrox'y quinolines, and particularly those which are non-migratory in the emulsions. Examples of the latter type compounds are:

6 stearoylamino-2-(2'-phenyl-6'-bromo-8'-hydroxy cinchoninoyD-amino toluene--sulfonic acid 2-phenyl-6-chloro-8-hydroxy cinchoninoyl octadecyl taurine 6 decoxy-3-(Z-phenyl-6-bromo-8-hydroxy-cinchoninoyl) -aminobenzene sulfonic acid 2 (3-stearoylaminophenyl) -6-bromo-8-hydroxy cinchoninic acid 2 stearoylamino 6 (6-chloro-8-hydroxy-cinchoninoyl)-aminotoluene-4-sulfonic acid, and the like.

Color formers for the cyan image are also described in my application Serial No. 101,913 and in USP 2,445,252, granted July 13, 1948 to Tulagin. Preferably these color formers are aryl-J- acid derivatives, particularly those containing a group rendering the color former non-migratory in the emulsion. Examples of the latter compounds are:

Dodecyl urethane of B-sulfoethyl-J-acid Tetradecyl urethane of p-anisyl J -acid 2-hexadecyl urethane of phenyl-J-acid 4-stearoylaminophenyl-J-acid, and the like.

The aromatic hydroxy compounds which are added to the 2,4-diamino aniline developers for the purpose of suppressing proximity development are phenols which are free from sulfo or carboxy groups. The presence of these groups in the phenol causes the phenol when present in the developer solution to inhibit or stop the color development process.

The phenols contemplated herein are typified by the following general formula:

wherein X and Y are hydrogen, halogen such as chlorine, bromine, iodine or fluorine, or an allphatic radical such as alkyl, i. e., methyl, ethyl, propyl, butyl or the like, hydroxyalkyl, such as hydroxymethyl, hydroxyethyl, hydroxypropyl, or the like, alkoxy, such as methoxy, ethoxy, and the like, hydroxyalkoxy, such as hydroxymethoxy. hydroxyethoxy, and the like.

Examples of such compounds are p-crescl, mcresol, p-fluorophenol, p-methoxyphenol, 2,4-dichloro phenol, o chlorophenol, 2,5-dibromo phenol, 3,6 di-iodo phenol, m bromophenol, p-iodophenol, p-ethylphenol, m-hydroxymethylphenol, p-methoxyphenol, m-ethoxyphenol, 2,4- dimethoxyphenol, p-hydroxymethoxyphenol, and the like.

The color developers in addition to containing the aforementioned 2,4-diamino anilines and the phenol will also contain the usual adjuncts such as an alkali, i. e., sodium carbonate, 9. preservative, i. e., sodium sulfite, an accelerator, i. e., a heterocyclic nitrogenous base such as pyridine, quinoline and the like, and a restrainer, i. e., potassium bromide, or the like.

The present invention may be carried out in the processing of any tripack to negative or positive images as by a direct subjection of the exposed material to color development or the development of a reversed image by color development.

The phenol or the derivative thereof employed is added to the color development solution. To effect the complete solution of the phenol, it has been found desirable to first dissolve it in a small amount of dilute trisodium phosphate solution (5 to 10%) before adding it to the color developer solution;

The following examples. illustratethe invention, but it is to be understood that the invention is not restricted thereto.

Example 1 A multilayer film composed of a red sensitive bottom layer containing 4-stearoylaminophenyl- J -acid, a green sensitive middle layer containing 2 stearoylamino- 6 -(6-chloro 8 hydroxycinchoninoyl)-aminotoluene-4-sulfonic acid, and a blue sensitive top layer containing 3-stear0ylamino 5 sulfobenzoylacetanilide was exposed, the latent image developed in a black and white developer, re-exposed, and the residual silver halide developed minutes in a solution of the following composition:

Sodium carbonate, monohydrate g Sodium sulfite g 40 Potassium bromide g 10 Phenol (in 100 cc. 10% trisodium phosphate) g 10 Pyridine g 14 4-(5 hydroxyethylamino) 6 -(4 methoxyphenylamino)-metanilic acid g 5 Water to -cc 1009 After development, the film was washed,

bleached in a ferricyanide bleach and fixed in an acid-hardening hypo. There was thus obtained a positive multicolor dye image, showing excellent color separation and brilliance.

Example 2 The procedure is the same as in Example 1, excepting that the phenol is replaced by p-cresol.

Example 3 The procedure is the same as in Example 1, excepting that the phenol is replaced by p-fiuorophenol.

Example 4 After development, the film is washed, bleached in a ferricyanide bleach and fixed in an acidhardening hypo solution. There is obtained a negative multicolored dye image, possessing excellent brilliance and color separation.

I claim:

1. In the process of producing subtractively colored azine dye images in a tripack, each silver halide emulsion layer of which is sensitized to one of the primary colors and each silver halide emulsion layer of which contains a color former capable of reacting with the oxidation products of 2,4- diaminoaniline to yield an azine dye image complimentary in color to the light for which the layer is sensitized by exposing the tripack and developing the same with a color developer containing as the effective developing agent a 2,4- diamino aniline in which the amino group in 4- position has the structure NR1R2 in which R1 is selected from the class consisting of hydrogen and aliphatic radicals, and R2 is selected from the class consisting of hydrogen, alkyl and aromatic radicals, and the amino group in 2-position has the structure NHR3 in which R3 is selected from the class consisting of aromatic radicals, a ring carbon atom of which is directly linked to the nitrogen atom and aliphatic radicals, a carbon atom of which is directly linked to the nitrogen atom, said carbon atom being substituted by at least 2 hydrogen atoms, the improvement which involves the suppression of proximity development which comprises incorporating in the color developer a phenol free from sulfo and carboxy groups and having in its molecule a single benzene ring.

2. The process as defined in claim 1 in which the phenol is added in an amount of 1 to 20 grams per liter of solution.

3. The process of producing azine dye images in a tripack, each silver halide emulsion layer of which is sensitized to one of the primary colors, the red sensitive layer containing an aryl-J-acid non-migratory in the emulsion as a color former, the een sensitive layer containing a G-halogen- S-hydroxy quinoline non-migratory in the emulsion as a color former, and the blue sensitive layer containing an open chain keto methylene compound non-migratory in the emulsion as a color former, which comprises exposing the tripack and color developing the same with a developer containing a 2,4-diamino aniline and a phenol free from sulfo and carboxy groups and having in its molecule a single benzene ring.

4. The process as defined in claim 3 wherein the phenol is present in the color developer in an amount of from about 1 to 20 grams per liter.

5. The process as defined in claim 3 wherein the 2,4-diamino aniline is a metanilic acid derivative containing an hydroxyalkyl amino group in the 4-position and an arylamino radical in the 6-position.

6. A color forming developer for the production of azine dye images comprising a solution of a 2,4-diamino aniline in which the amino group in 4-position has the structure NR1R2 in which R1 is selected from the class consisting of hydrogen and aliphatic radicals, and R2 is selected from the class consisting of hydrogen, alkyl and aromatic radicals, and the amino group in 2- position has the structure NHR3 in which R: is selected from the class consisting of aromatic radicals, a ring carbon atom of which is directly linked to the nitrogen atom and aliphatic radicals, a carbon atom of which is directly linked to the nitrogen atom, said carbon atom being substituted by at least 2 hydrogen atoms and a small amount of a phenol free from sulfo and carboxy groups and having in its molecule a single benzene ring.

7. The composition as defined in claim 6 in which the 2,4-diamino aniline is a metanilic acid derivative in which the 4-position is substituted by an hydroxyalkylamino group and the fi-position by an arylamino group.

ROBERT C. GUNTHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,350,109 Hanson May 30, 1944 2,414,491 Tulagin Jan. 21, 1947 2,449,919 Weissberger Sept. 21, 1948 2,486,440 Schmidt Nov. 1, 1949 

1. IN THE PROCESS OF PRODUCING SUBSTRACTIVELY COLORED AZINE DYE IMAGES IN A TRIPACK, EACH SILVER HALIDE EMULSION LAYER OF WHICH IS SENSITIZED TO ONE OF THE PRIMARY COLORS AND SAID SILVER HALIDE EMULSION LAYER OF WHICH CONTAINS A COLOR FORMER CAPABLE OF REACTING WITH THE OXIDATION PRODUCTS OF 2,4DIAMINOANILINE TO YIELD AN AZINE DYE IMAGE COMPLIMENTARY IN COLOR TO THE LIGHT FOR WHICH THE LAYER IS SENSITIZED BY EXPOSING THE TRIPACK AND DEVELOPING THE SAME WITH A COLOR DEVELOPER CONTAINING AS THE EFFECTIVE DEVELOPING AGENT A 2,4DIAMINO ANILINE IN WHICH THE AMINO GROUP IN 4POSITION HAS THE STRUCTURE -NR1R2 IN WHICH R1 IS SELECTED FROM THE CLASS CONSISTING OF HYDROGEN AND ALIPHATIC RADICALS, AND R2 IS SELECTED FROM THE CLASS CONSISTING OF HYDROGEN, ALKYL AND AROMATIC RADICALS, AND THE AMINO GROUP IN 2-POSITION HAS THE STRUCTURE -NHR3 IN WHICH R3 IS SELECTED FROM THE CLASS CONSISTING OF AROMATIC RADICALS, A RING CARBON ATOM OF WHICH IS DIRECTLY LINKED TO THE NITROGEN ATOM AND ALIPHATIC RADICALS, A CARBON ATOM OF WHICH IS DIRECTLY LINKED TO THE NITROGEN ATOM, SAID CARBON ATOM BEING SUBSTITUTED BY AT LEAST 2 HYDROGEN ATOMS, THE IMPROVEMENT WHICH INVOLVES THE SUPPRESSION OF PROXIMITY DEVELOPMENT WHICH COMPRISES INCORPORATING IN THE COLOR DEVELOPER A PHENOL FREE FROM SULFO AND CARBOXY GROUPS AND HAVING IN ITS MOLECULE A SINGLE BENZENE RING. 